libdvdnav is a library for developers of multimedia applications.  It
allows easy use of sophisticated DVD navigation features such as DVD
menus, multi-angle playback and even interactive DVD games.  All this
functionality is provided through a simple API which provides the DVD
playback as a single logical stream of blocks, intermitted by special
dvdnav events to report certain conditions.  The main usage of libdvdnav
is a loop regularly calling a function to get the next block, surrounded
by additional calls to tell the library of user interaction.  The whole
DVD virtual machine and internal playback states are completely
encapsulated.
